GDI+ will certainly be around for quite a while. But in my opinion GDI+ is already a bit outdated because it is not flexible and Microsoft has not added any new functions for a long time. GDI+ only uses C# and VB.NET from the System.Drawing namespace and even there some GDI+ functions are missing. UWP, WPF etc. use WIC and Direct2D in the form of WinRT, XAML and the App SDK. I cannot imagine Windows itself using GDI+ to render windows.